The present invention relates in general to the field of pantyhose manufacture, and in particular to a new and useful method and apparatus for automatically positioning the two tubular legs (or hose blanks) of a pantyhose over the tubes of a suction everter in a toe-closure machine in order to perform a correct and accurate sewing of the toes.
Known toe-closure machines include suction everter tubes which provide a support for turning the tubular legs or hose blanks inside out. Two side fingers are longitudinally slidable relative to the everter tubes and provide for the transfer of the hose toe to be sewn in a sewing machine associated with the toe-closure machine.
U.K. Pat. No. 1,577,758 discloses an automatic device for placing the end toe of a hose blank to be sewn, at a predetermined position on the tube of the suction everter. The suction everter includes a fixed position-sensor (e.g. a photoelectric cell) capable of detecting a detail (e.g. the free end) of the hose, and further includes hose gripping means which cooperate with the side fingers of the everter to first shift the hose forwared, that is toward the free end of the tube in order to make the detail move past the sensor, and then backward until the hose detail reaches a position corresponding to the sensor thereby causing the sensor to initiate the opening of the gripping means.
This known device includes gripping means which always clamp the hose at the same position relative to the tube and push the hose along a path of constant length. Moreover, since the freed end of the hose, once its eversion on the tube has been completed, is at a position which may vary within broad limits, the gripping means always clamp the hose at some distance from its end. Accordingly, during the forward motion of the hose, that is in the direction of the free end of the tube, several creases (or puckers) are bound to occur in the hose end zone which is not engaged by the gripping means. This happens even if the hose is moved at a low speed. To remove these creases it is necessary to draw the hose back at low speed.